[itsme]

If you go to Settings - Library Settings - Song Title Formatting and specify a title format with the composer first, e.g. %COMPOSERS% - %TITLE% and check the checkbox "Use formatted title for sorting" in the sort options the list will be sorted by composer. Be aware that "Composers" is plural, it's a multi-value field - there might be surprises in the sort order.

With
%COMPOSERS:${VALUE} - %%TITLE%
you can avoid the preceding " - " in those cases where no composer is specified, but the sort order is a mix of titles and composers.